Gripper mechanism for printing-presses



- 2 Sheets-Sheet 1.

(No Model.)

J. T. HAWKINS. I GRIPPER MECHANISM FOR PRINTING PRESSES.

Patented July 24, 1883.

[NVENTOR A TTORNEY- N. PETERS. Finale-Lithographer. \hashinglnn. D. c.

2 Sheets-Sheet 2 (No Model.)

' J. T. HAWKINS. GRIPPER MECHANISM FOR PRINTING PRESSES.

Patented July 24, 1883.

A TTORNE Y N. PETKRS Pmmum n m. Wampum o. c."

UNITED STATES PATENT OFFICE.

JOHN T. HAIVKINS, OF TAUNTON, MASSACHUSETTS.

GRIPPER MECHANISM FOR PRINTING-PRESSES.

SPECIFICATION forming part of Letters Patent No. 281,763, dated July 24, 1883.

Application filed August 30, 1832.

' set forth and illustrated in the following specifieation and accompanying drawings.

The object of this invention is to prevent fracture of the mechanism in case the cylindergrippers should happen to be misplaeedthat is, open when they should be closed, and vice versawhen the press is started in motion, and also to automatically readjust the grippers if so misplaced.

To this end the invention consists of certain combinations of devices, hereinafter particularly described and claimed, whereby the gripper mechanism automatically adjusts itself to perform its proper offices, thus obviating in jury or fracture of the parts or stoppage of the machine, should the grippers by any chance happen to be open when they should be closed, or vice versa.

This invention may be applied to all presses in which the grippers are opened and closed by means of a slotted tumbler-cam secured to a rocking gripper-shaft, said cam being operated by movable or sliding studs alternately entering its slot, thus causing the cam to rock or vibrate through the proper angle for opening and closing the grippers. In those presses whose cylinders make more than one revolutionto an impression sliding studs have been operated by various mechanisms to respectively engage the slot of the tumblencam for alternately opening and closing the grippers secured to the shaft operated by said cam but unless some means be provided for automatic adjustment of said cam and studs, in addition to the sliding motion of the studs, fracture of the mechanism may ensue, if, in starting the press, the grippers be set open instead of closed, for in such case the position of the tumbler-cam will be such that the slot in the cam will not be presented to the first stud encountered, and injurious collision of the cam and stud will occur.

In the accompanying drawings the parts shown illustrate my invention as applied to a two-revolution printing-press.

In said drawings, Figure 1 is a side eleva- (No model.)

tion, and Fig. 2 an elevation at right angles thereto, of apart of the cylinder and upper half of one of its journal-boxes, which parts carry the principal devices constituting the gripper mechanism. Figs. 8, 4, and 5 are enlarged views, partly in section, taken at the line 00 m in Fig. l, and showing the closingstud and its carrier. Fig. 6 similarly shows the other or opening stud and its carrier, taken at the line 1 3 in Fig. 1.

In said figures, the letter a indicates a part of one end of the cylinder; b, the upper half of the cylinderjournal-box, extended into the necessary brackets for supporting or retaining the sliding studs, hereinafter described 5 c, the cylinder-shaft, and (l a pinion secured thereto and gearing with aspur-wheel, 6, carried upon a shaft, f, j ournaled'in the bearing b. Said pinion and spur-wheel h. ve a multiple of gearing of two to one. f is secured afivabbling cam, g, of such a warped sideedge surface as to cause the opening-stud 71 and closing-stud i to be alternately protruded toward and withdrawn from the end of the cylinder, the slots 8 sin the tail end of said studs engaging the periphery of said cam for that purpose. Thus at one revolution of the cylinder (1, if the stud i is protruded and the stud h withdrawn, as shown in Up on the shaft Fig. 2, at the next revolution the position of said studs will be reversed, the stud h being protruded and the stud i withdrawn. Said studs are carried in extensions of the bearing 1), which extensions form bearings for them, as shown in the drawings. A slotted tumblercam, j, is secured to the gripper-shaft k, and a stop, Z, upon the end of the cylinder, limits the two positions of said tumbler-cam. The rod m is pivoted to the cam j, and the free end of said rod slides freely throughalug, 12, upon the cylinder-head a. Said rod carries a helical spring, n, reacting between the lug p and an adjustable collar, 0, on the rod. The point of attachment of the rod m to the tumblercam j, in passing to either side of the center of oscillation of the gripper-shaft k, for the two positions of said cam as limited by the stopl on either side, tends to hold said cam against said stop in either case. In Fig. 1 the tumbler-cam j is shown at B in full lines, and at B B in dotted lines, in which positions the grippers are open, and in the positions of said cam indicated at A A A the grippers are closed. As shown at B in full lines, and the cylinder moving in the direction of the arrow, the tumbler-cam j is in position to engage the stud i, and in passing the same would be rotated by it into the position shown at A, leaving the grippers closed, the stud h being withdrawn, as shown in Fig. 2, to allow said tumbler-cam to pass; but were the tumbler-cam in the position shown at A, Fig. 1, as may sometimes be the case through error of the pressman, its upper straight exterior surface would encounter the protruded stud t in the position shown at A, in which event fracture of some part would occur unless provided against by some suitable means. In order to guard against such contingency, the studs and h are jointed, as shown atm, Figs. 3, 4, 5, and 6, the stud i being so located and held from rotation in its bearing by the edge of the cam operating in the slot 8 in the tail of said stud, that the jointed part i of said stud may be flexed in a line or plane coinciding with a radius of the cylinder a, the carrier b of the stud being slotted out at its top, as shown in Figs. 3, 4, and 5, to allow of the flexing upward of the jointed parts when protruded by the cam hen said cam withdraws the stud i, the part i, if upraised, is necessarily flexed downward and straightened by contact with the rounded edge or corner t of the unslotted part of the carrier Z), the stud and its jointed part passing into said carrier as into a sheath. If, now, the tumbler-can1 j were in the position A, Fig. 1, this position being exactly the reverse of what it should be when the stud i is protruded, as shown in Fig.

2, the straight exterior surface of said cam as the cylinder revolves will flex the jointed part 1'. of the stud t out of its way into the position shown by the dotted lines i, Fig. 3. The tumbler-cam, upon the succeeding revolution of the cylinder, will next encounter the jointed part h of the stud 7b in its proper position, the jointed part c" of the stud in the meantime having been reflexed into its normal position, as shown in full lines in Fig. 3, by the action of the cam g in withdrawing said stud within its carrier b, as before explained. Should the tumbler-cam 7" be in the position shown at B, Fig. 1, with the stud i withdrawn and the stud 71. protruded, (the reverse of their positions shown in Fig. 2,) the straight exterior surface of the tumbler-cam will meet the stud h in the position shown at B, Fig. 1, and flex its jointed part 71 downward in the line or plane ;1 y out of the slot in its carrier 7), the tumbleream remaining in proper position for its slot to engage the protruded studt at the succeeding revolution of the cylinder, and the stud h being withdrawn within its carrier and its jointed part It reflexed into its normal position simultaneously with. the protrusion of the stud 2' by the cam which cam operates both to protrude and withdraw each stud, as before explained.

-.- enres The above explanation and description applies to the proper ahead motion or advancing revolution of the press; but'the same danger of fracture remains unprovided for by the above-described means in running the press backward either by hand or power if the grippers be misplaced. In order to obviate this danger, the opposite exterior surface of the tumbler-cam j is given a double inclination from about the point of attachment of the rod m, which conformation serves to flex the stud i or the stud 71., as the case may be, in backing the press, in the same manner as is done by the straight exterior surface of said cam when the cylinder revolves ahead.

A, small pin, a, with a rounded. point is entered through the side of the carrier 1) into its bore, and slides freely within its hole or seat. The point of said pin bears lightly upon the jointed part i of the stud i, the pin being held in place by a spring, o. Said spring is secured to the carrier b by the screw 10. The object of this arrangement is to prevent the j ointed part a? of the sliding stud from being jarred upward while protruded from its carrier by vibration in the machine, or by other slight accidental cause, and thus fail to be in position. to meet the slot of the tumbler-cam j. The effort exerted by said cam when its slot engages the stud is alwys exerted in all positions, as hereinafter shown, to reflex and straighten the j ointed part c" downward against the inner circumference of the half-cut part of the carrier 1). The sliding stud 71., its jointed part h, and its carrier I) are made the same in all respects as just described for the stud 1'. and its jointed part i and carrier 1), except that the'slot in the latter carrier opens upward in a line or plane, 00 a", coinciding with a radius of the cylinder (6, whereas the other carrier has its slot opening downward, but in a line or plane, 1 y, also coinciding with a radius of the same cylinder, the small sliding pin a and its spring 1) serving to prevent the jointed part h of the stud 7L from flexing out of the slotted or half-cut end of its carrier 1) by its own weight. It will be observed that when the tumbler-cam j enters upon the stud i from the position shown at B the effort of the spring a is exerted to depress or flex the jointed part i against theinner circumference of the half-cut end of its carrier I) until the slot in the tumbler-cam j has reached the position shown at C, Fig. 1,

, coinciding with the radial line :0 x, at which time the center of the pivot of the rod m, by

which pivot said rod is attached to the tunibler-cam j, will coincide with a line drawn from the point 7a to the point p, when the spring a will no longer exert any effort to rotate the tumbler-cam j in either direction. As soon, however, as this position is passed, the effort of the spring a is again exerted to fun ther rotate the tumbler-cam j in the same direction in which it was moving when so arrested. Said effort will therefore continue to exert a downward pressure upon the jointed IIO part i of the studi until said part has entirely passed out of the slot in the tumbler-cam j, as at A.

It will thus be seen that all the legitimate pressures resulting from the operation of the mechanism tend to reflex, force, or hold the jointed parts i 71/ of the studs zh into their respective seats in the half-cut ends of the carriers I) b, the pins and springs 12 being required solely to prevent accidental flexure of the jointed parts a" ll/,'and the possibility of downward flexure at the wrong time of the jointed part h by its own weight. The explanation above given of the downward pressure exerted upon the j oiuted part of the stud i by the spring a through the slotted tumbler-cam j applies also to the action through said cam exerted upon the jointed part h by the spring a, except that in this case all the pressure of said spring will be exerted upward in or about in a line coinciding with the radial line 3 3 thus tending to reflex, force, or hold thejointed part h in its seat in the half-cut end of its carrier 7), in the manner described for the jointed part i, and as shown in the three positions of thetumbler-camj at A B C, Fig. 1.

From the description and explanation above given it can now be clearly seen that those parts of the mechanism designed to prevent breakage are brought into use only when maladjustment of parts has been made by accident or otherwise, and in the absence of maladjustment said parts operate precisely as though no provisions to prevent breakage had been made; and when such mal-adjustment occurs the whole mechanism automatically readjusts itself to fulfill all its offices, and re stores the proper and normal relation of all its parts.

Having thus fully described my said improvement, as of my invent-ion, I claim 1. In the gripper mechanism of a printingpress, in combination with a slotted tumblercam secured to a gripper rock-shaft, hinged studs constructed to slide in slotted carriers, whereby said cam is operated to open and close the grippers, and also operates to flex said studs out of its path when said studs fail to enter into or articulate with its slot, substantially as and for the purposes described.

2. In the gripper mechanism of a printing press, in combination with a slotted tumblercam and a hinged studconstructed to operate said cam and to be flexed by it, a retainingpin, a, and a spring, '0, all substantially as and for the purposes described.

JOHN T. HAXVKINS.

\Vitnesses:

ELISHA T. JACKSON, JOHN F. lllon'rooimnv. 

